An electrical substation is a subsidiary station of electricity generation, transmission and distribution where voltage is transformed from high to low or vice-versa using transformers. Electrical substations are usually provided with a control module which monitors and controls the different elements and functions of the substation. These elements comprise disconnectors, disconnect switches, circuit breakers and other high voltage switch gears. As electrical substations are operated with high voltage, the control modules have to be protected and isolated from this high voltage so that the components of the control module will not be damaged by electromagnetic interferences (EMIs) or radio frequency interferences (RFIs).
The protection of control modules is limited to voltage surges of the order of 1000-1500 V. Therefore, there is a need to provide control modules that safely operate in environments of higher voltage surges.